In medical and other types of laser applications, laser delivery handpieces are widely used. With the development of optical fibers and solid-state lasers, complex arrangements of collimating lenses, mirrors and filters have been replaced with small, efficient laser delivery devices utilizing fiber optics.
U.S. Pat. No. 5,020,995 issued Jun. 4, 1991 to Levy teaches a surgical treatment and method for cutting tooth tissue. A handpiece for cutting dentin and enamel is disclosed which contains a hollow tube connected to an external source of cooling fluid. The apparatus has a number of drawbacks, however, including the need for peripheral tubing and other connections to control and laser source. In practice, these plurality of external connections make the device awkward to use. Furthermore, if the coolant source is located farther than about 0.5 to about 1.0 meter from the outlet end positioned to direct coolant onto the tissue being cooled, either significant insulation is required or a considerable purge time will be necessary to deliver coolant fluid at a low temperature to the desired location on demand.
U.S. Pat. No. 5,344,418 issued Sep. 6, 1994 to Ghaffari teaches an optical system for treatment of vascular lesions. In addition to the drawbacks noted above, principally the need for external connections and complicated piping, insulation and purging requirements, the cooling system in intended to cool the sapphire lens of the system. The patent also refers to a system for the control of skin temperature.
Recently, a great deal of attention has been given to selective cooling of biological tissue during thermally mediated therapeutic procedures. B. Anvari et al., Selective Cooling of Biological Tissues: Application for Thermally Mediated Therapeutic Procedures, Phys. Med. Biol. 40 (1995) 241-252. Methods and systems have been proposed based on models of heat conduction in various types of tissue at various levels beneath the skin. In certain dermatological applications the objective has been to produce a photo and/or thermal effect primarily to subsurface tissue, without destroying or altering superficial structures. Examples of such procedures include laser treatment of port wine stains and the clinical treatment of other dermatoses, lesions and tattoos. Experiments have been performed that use, for example, infrared radiometry to measure the thermal response of in vivo human skin to cooling by a cryogen spurt.
While a information has been gained from these studies and others about the effect of such cooling on biological tissue during such operations, very little effective or efficient equipment is commercially available. Often, applying spurts of cryogenic materials to a site of laser delivery results in splashing of the cryogenic liquid and/or unconfined and uncontrollable cooling.
Therefore, it is an advantage of the present invention to provide an improved handpiece for performing thermally mediated medical, therapeutic, cosmetic and other procedures with selective cooling of surface tissue.
It is a further advantage of the present invention to provide a light, unrestricted handpiece for such procedures.
It is a further advantage of the present invention to provide an apparatus with an on-board cryogen or other coolant fluid reservoir.
It is a further advantage of the present invention to provide such apparatus which allows visualization of the remaining amount of coolant fluid and which is refillable.
It is a further advantage of the present invention to provide such apparatus in which both coolant and laser energy are both delivered in a controlled, confined manner to avoid delivery of both laser energy and coolant to undesired locations.
It is a further advantage of the present invention to provide such apparatus with a refillable cryogen fluid reservoir.
It is a further advantage of the present invention to provide such apparatus with a removable cryogen fluid reservoir.
It is a further advantage of the present invention to provide a handpiece for delivering energy such as from a laser or other therapeutic device to target tissue, the handpiece having an on-board cooling system comprising individual disposable or re-usable cylinders or cartridges of cryogen or other cooling fluid which couple to the handpiece and can be replaced conveniently and efficiently as needed.
It is a further advantage of the present invention to provide a handpiece with coolant for delivering energy, including laser, radio frequency, ultrasound and other sonic energy, electromagnetic, chemical, mechanical and other types of energy.
It is a further advantage of the present invention to provide methods of using such apparatus, in medical and aesthetic procedures including but not limited in any way to wrinkle removal, hair removal, tattoo removal, port-wine and other pigmentation adjustment, etc.
It is a further advantage of the present invention to provide apparatus and methods for reformation of collagen.